Madonna's 12th studio album, MDNA, had the biggest single-day pre-order in iTunes history prior to its release this week.

But while the album is looking good sales-wise, its critical reception has been mixed. The Guardian's Alexis Petridis said:

Neither the return to form it thinks it is, nor the disaster Madonna should rightly have delivered at some stage in her musical career but never quite has ... Instead, MDNA turns out to be just another Madonna album.

If you'd only heard the singles from MDNA you'd mistakenly think it was as much of a dud as its predecessor, 2008's Hard Candy ... Yet the more relaxed, less stentorian tracks sparkle. And the final stretch, all of it co-produced by her most longstanding and sympathetic collaborator, William Orbit, sounds as if it's been borrowed from an entirely different and much better project.

What do you think of Madonna? Will you be buying MDNA? Is her best work still in front of her? Or is time for her to hang up her microphone?